1. Field of the Invention
The present invention relates to an automotive AC rotating machine.
2. Description of the Related Art
FIG. 2 is a section view showing a conventional automotive AC rotating machine (hereinafter, an automotive AC rotating machine is often referred to merely as a rotating machine). Referring to the figure, the rotating machine comprises: a first bracket 51; a Landor type rotor 53 which is disposed in the first bracket 51, and which is fixed to a rotor shaft 52; a stator 54 which is fixed to an inner wall face of the first bracket 51; a slip ring 55 which is fixed to an end portion of the rotor shaft 52 to supply a current to the rotor 53; a pair of brushes 56 which are in sliding contact with the surface of the slip ring 55; and a brush holder 58 which houses the brushes 56 and springs 57 pressing the brushes 56.
The rotor 53 comprises a field winding 59 through which a current flows to generate magnetic fluxes, and a rotor core 60 which covers the field winding 59. The stator 54 comprises a stator core 61 through which the magnetic fluxes from the field winding 59 pass, and in which plural steel plates are stacked, and a three-phase stator winding 62 through which a three-phase current flows.
The rotating machine further comprises an electromagnetic clutch 64 which is disposed in a second bracket 63, a planetary gear mechanism 65, a pulley 66, and a one-way clutch 67.
The electromagnetic clutch 64 comprises: an electromagnetic clutch body 70 which is fixed to the second bracket 63 by fixing means 69 such as a fixing screw 68 and a key; a field coil 71 which is disposed in the electromagnetic clutch body 70; an electromagnetic clutch driven member 75 which is fixed by a fixing screw 73 via a holding member 72 of the first bracket 51, which is opposed to the electromagnetic clutch body 70, and which has an engaging portion 74; and a spring 76 which is disposed between the electromagnetic clutch driven member 75 and the head of the fixing screw 73, and which urges the electromagnetic clutch driven member 75 toward the opposite side of the electromagnetic clutch body 70.
A guide face 72a is formed on the outer peripheral face of the holding member 72. The electromagnetic clutch driven member 75 is attached to the holding member 72 by causing a guide face 75b which is formed on the inner peripheral face of the electromagnetic clutch driven member 75, to axially slide over the guide face 72a. Alternatively, the holding member 72 of the first bracket 51 may be integrally molded instead of being formed as a separate member.
The planetary gear mechanism 65 comprises: a sun gear 77; a cylindrical member 80 in which an engaging portion 78 that is to be engaged with the engaging portion 74 of the electromagnetic clutch driven member 75 is formed in an end face, and an internal gear 79 is formed in the inner wall face; a bearing 81 which is disposed between one end face of the cylindrical member 80 and an end portion of the first bracket 51; a planet gear 82 which meshes with the internal gear 79 and the sun gear 77; a planet gear shaft 84 which is passed through a center portion of the planet gear 82 via a bearing 83; a carrier 85 which rotatably supports the planet gear 82 via the planet gear shaft 84, and which is configured integrally with the pulley 66; and a bearing 86 which is disposed between an end portion of the carrier 85 and that of the cylindrical member 80.
The one-way clutch 67 comprises: a cam portion 87 which is disposed inside the carrier 85; bearings 88 which are disposed respectively on both sides of the cam portion 87; and a driven member 90 which is fixed together with the sun gear 77 to an end portion of the rotor shaft 52 via a fixing key 89.
The reference numerals 91 and 92 denote bearings, 93 and 94 denote spacers, and 95 denotes a fixing bolt.
Next, the operation will be described.
The motor operation of the rotating machine will be first described.
When an engine is to be started, the field coil 71 of the electromagnetic clutch 64 is energized, the electromagnetic clutch driven member 75 is driven against the elastic force of the spring 76 to be joined with the electromagnetic clutch body 70, and the engaging portion 74 of the electromagnetic clutch driven member 75 is engaged with the engaging portion 78 of the cylindrical member 80.
As a result, the internal gear 79 of the cylindrical member 80 functions as a fixed element, so that speed reduction at the reduction ratio of the planetary gear mechanism 65 is enabled. With respect to the rotating force of the rotor 53, the sun gear 77 functions as an input element, and the rotation of the sun gear 77 causes the planet gear 82 to revolve around the sun gear 77 while rotating about the planet gear shaft 84.
In accordance with the revolution of the planet gear 82, the carrier 85 functions as an output element, the pulley 66 which is integrated with the carrier 85 rotates, and the rotating force is transmitted to the engine via a belt (not shown) which is wound around the pulley 66, whereby the engine is started. At this time, the one-way clutch 67 operates idle. Therefore, the engine is driven by a product of the rotational speed of the rotor 53, the reduction ratio of the planetary gear mechanism 65, and that of the pulley 66 and a crank pulley (not shown) of the engine.
The rotating force of the rotor 53 is obtained by supplying an exciting current to the field winding 59 via a battery (not shown), the brushes 56, and the slip ring 55 to generate magnetic fluxes in the rotor core 60, and, in this state, supplying a three-phase current to the three-phase stator winding 62.
Next, the generator operation of the rotating machine will be described.
When an electric power is to be supplied by the generator operation, the energization of the field coil 71 of the electromagnetic clutch 64 is interrupted, so that the electromagnetic clutch driven member 75 is separated from the electromagnetic clutch body 70 by the elastic force of the spring 76 to cancel the engagement of the engaging portion 74 of the electromagnetic clutch driven member 75 and the engaging portion 78 of the cylindrical member 80, thereby enabling the cylindrical member 80 to rotate. Under this state, the power from the engine is transmitted via the pulley 66 to the carrier 85 functioning as an input element. At this time, the one-way clutch 67 performs an engaging action. In accordance with the rotation of the carrier 85, therefore, the rotor 53 is caused to rotate via the rotor shaft 52, and an electromotive force is generated in the three-phase stator winding 62.
Since the conventional automotive AC rotating machine is configured as described above, the planetary gear mechanism 65 is assembled in the following manner. First, the one-way clutch 67 is previously attached to the inside of the carrier 85, and the inner periphery of the bearing 86 is then fitted onto the outer periphery of the carrier 85. Thereafter, the planet gear shaft 84 which holds the planet gear 82 via the bearing 83 is fitted into the carrier 85, whereby a sub assembly is configured. The sub assembly and all must be pressingly inserted along the outer periphery of the bearing 86 into the inner periphery of the cylindrical member 80. Therefore, the rotating machine has a problem in that it is very difficult to assemble the machine.
In the pressing fitting process, furthermore, the outer race of the bearing 86 is press-inserted into the inner periphery of the cylindrical member 80 by pressing the inner ring of the bearing 86. This produces another problem in that an impression is produced in a shoulder portion of a race surface in the bearing 86.
The invention has been conducted in order to solve the problems discussed above. It is an object of the invention to provide an automotive AC rotating machine which can be easily assembled, and in which it is possible to avoid occurrence of a failure and a damage of a part during the assembling process.
The automotive AC rotating machine according to a first aspect of the invention comprises: a rotor which is fixed to a rotor shaft disposed in a bracket; a sun gear which is fixed to an end portion of said rotor shaft; a planet gear which meshes with said sun gear; a cylindrical member having an internal gear which meshes with said planet gear; a carrier which rotatably supports said planet gear via a planet gear shaft that axially passes through a center portion of said planet gear; a one-way clutch which is disposed in said carrier and which transmits a rotating force from a power transmission mechanism to said rotor shaft via said sun gear; and an electromagnetic clutch which is disposed in said bracket, wherein said one-way clutch and said sun gear are configured integrally with each other.
In the automotive AC rotating machine according to a second aspect of the invention, said power transmission mechanism, said one-way clutch, and said sun gear are configured integrally with each other as a sub assembly, and said planet gear and said carrier are configured integrally with each other as a sub assembly.
In the automotive AC rotating machine according to a third aspect of the invention, said carrier and said power transmission mechanism are to be connected to each other, said carrier and said power transmission mechanism are subjected to radial positioning by coaxially fitting an outer periphery of one end portion of said power transmission mechanism and an inner periphery of said carrier.
In the automotive AC rotating machine according to a fourth aspect of the invention, said carrier and said power transmission mechanism are connected to each other by coupling means such as a screw.
In the automotive AC rotating machine according to a fifth aspect of the invention, said carrier and said power transmission mechanism are integrally fitted and coupled to each other by a pin.
In the automotive AC rotating machine according to a sixth aspect of the invention, said carrier and said cylindrical member configure a labyrinth.